The feeding and uniform distribution of loose material, such as granules, pellets, powders and the like onto continuously moving supports presents a great many problems. In particular, while it may be a relatively simple matter to feed a support such as a straight belt with uniform distribution, greater difficulties are encountered when dealing with the same problem with a rotary platform. This is largely due to the fact that, given a constant material feed speed, the speed of displacement of the rotary platform increases from the center of the platform to its perimeter. Consequently more material will be deposited near the center than near the outer edge.
In certain sectors, such as metallurgy, it is of the greatest importance to achieve equal distribution of the material sent for processing in rotary-hearth furnaces, which present precisely the problems described above. The unsatisfactory distribution of the material can in fact lead to a poorer yield of the process and hence to inferior product quality.